延迟焦化装置吸收稳定系统操作优化

延迟焦化装置生产特点装置连续生产,焦炭塔间歇操作,焦炭塔的周期切换使焦化瓦斯发生周期变化,对延迟焦化吸收稳定系统造成影响,尤其干气C3以上经常超标。本文通过对延迟焦化吸收稳定系统的分析,提出优化、细化操作的方法和措施,提高装置运行的平稳性和经济效益。     

延迟焦化装置能耗分析探讨

延迟焦化是对石油进行二次加工的技术,由于其技术简单、容易操作,近年来受到越来越多的关注和广泛应用。焦化过程是唯一能生产石油焦的工艺手段。延迟焦化装置具有延迟作用,保证焦化油在反应炉内不生焦;延迟焦化装置可以处理一些较为劣质的渣油、焦炭,提高石油的利用率。但同时延迟焦化装置也会带来严重的能耗问题。本文主要探讨和分析了延迟焦化装置的能耗,希望及时采取有效措施,将能耗降到最低,获取最大的经济效益和社会效益,最大限度的优化延迟焦化装置。     

关于焦炭塔底冷焦水排水管堵塞问题解决方法的一点探索

中石油辽河石化分公司2004年投入使用的100万t/a延迟焦化装置是国内首套超稠油直接焦化装置。与现有的渣油焦化装置相比，超稠油直接焦化装置由于油品性质的特殊性，在焦炭塔内结焦过程中时常出现弹丸焦和粘油，致使焦炭塔底冷焦水排水管堵塞的现象在开工初期经常发生，经过生产过程的优化调整，会有所好转，但还偶有发生。这种情况一旦出现，使塔内冷焦水无法排除，人工清堵时经常出现热水烫伤人的事故，给公司的安全生产带来很大隐患。     

延迟焦化装置停工检修作业中的危险分析和防范措施

延迟焦化是加工重质油的一种工艺技术，通过将重质渣油送至焦化加热炉，加热至合适的温度，然后送至焦炭塔，停留足够的时间后进行深度裂化反应，最终将渣油转化为气体和轻、中质馏分油及焦炭等产品，具有技术成熟、投资少、转化率高的优点。但是，装置经过长时间的运行后，需要对其进行停工检修，以便于对老旧设备进行更新，对装置平时生产过程中出现的问题进行工艺或技术改造。为了提高延迟焦化装置的检修效率，降低检修过程中发生事故的概率，确保检修过程的安全，分析了某延迟焦化装置从停工到检修过程中所存在的主要危险因素，并提出了相应的防范措施，以降低停工检修成本，确保停工检修能够安全平稳进行。     

延迟焦化装置节能技术分析

延迟焦化装置是石油工业能耗的“大户”,应该对延迟焦化装置的节能进行深入思考,本文立足于延迟焦化技术运用的实际工作,分析了导致延迟焦化装置能耗过高的原因,提供了降低燃料消耗、降低蒸汽消耗、增设变频电力设施等措施,希望对提高延迟焦化装置的节能技术做出时代的思考,起到在技术层面上和工作层面上提升延迟焦化装置节能降耗水平的作用,为实质降低延迟焦化装置能耗,实现石油工业节能、长期发展打好坚实的技术基础。     

预测控制在焦化加热炉的应用

延迟加热炉是延迟焦化装置的核心设备,其控制品质直接关系到整个装置的安全生产、能耗和装置效益。本文简要介绍了在中石化长岭分公司应用基于状态空间模型的预测控制和专家规则控制实现延迟焦化加热炉先进控制的设计、开发过程以及先进控制应用效果。     

延迟焦化装置加工劣质油出现的问题及对策

介绍了延迟焦化装置加工劣质油时的生产现象及影响,通过对生产过程的具体分析,提出了优化延迟焦化原料性质和操作参数的具体措施,在实施这些措施后避免了弹丸焦的生成,实现了装置安全和平稳生产。     

煤系针状焦延迟焦化加热炉炉管结焦的探讨

对于煤系针状焦生产,延迟焦化装置无论从产量还是质量考虑都是核心部分。而延迟焦化加热炉则是延迟焦化装置的核心部分。在延迟焦化生产中,加热炉为焦化反应提供足够热量。物料在加热炉管中停留一定的时间,达到成焦温度,经转油线进入焦炭塔成焦。在该过程中,由于物料高残炭、高密度、高黏度,临界反应温度低的特性,经长期运行     

浅析延迟焦化装置分馏塔底结焦原因及措施

延迟焦化装置是炼油行业中渣油转化的重要手段,延迟焦化装置主要由加热炉、焦炭塔、分馏塔等主要设备组成,其中分馏塔的作用是将焦炭塔反应来的高温油气进行多次冷凝和气化,分别从侧线及顶部馏出蜡油、柴油、汽油、富气等产品,是延迟焦化装置非常关键的生产设备。分馏塔底易结焦一直是制约延迟焦化装置安全、平稳、满负荷、长周期运行的主要因素。     

Discussion on coking reason and prevent of fracfionating column bottom in delayed coking unit

延迟焦化装置是炼油行业中渣油转化的重要手段,延迟焦化装置主要由加热炉、焦炭塔、分馏塔等主要设备组成,其中分馏塔的作用是将焦炭塔反应来的高温油气进行多次冷凝和气化,分别从侧线及顶部馏出蜡油、柴油、汽油、富气等产品,是延迟焦化装置非常关键的生产设备.分馏塔底易结焦一直是制约延迟焦化装置安全、平稳、满负荷、长周期运行的主要因素.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.